Registration of media type image/svg+xml
Chris Lilley
chris at w3.org
Thu Dec 8 05:12:25 CET 2005
Hello ietf-types,
The SVG WG requests feedback on its standards tree media type
registration for image/svg+xml:
http://www.w3.org/TR/2005/WD-SVGMobile12-20051207/mimereg.html
M.1 Introduction
This appendix registers a new MIME media type, "image/svg+xml" in
conformance with RegMedia and W3CRegMedia.
http://www.ietf.org/internet-drafts/draft-freed-media-type-reg-05.txt
http://www.w3.org/2002/06/registering-mediatype.html
M.2 Registration of Media Type image/svg+xml
MIME media type name:
image
MIME subtype name:
svg+xml
Required parameters:
None.
Optional parameters:
None
The encoding of an SVG document shall be determined by the
XML encoding declaration. This has identical semantics to the
application/xml media type in the case where the charset
parameter is omitted, as specified in RFC3023 sections
8.9, 8.10 and 8.11.
Encoding considerations:
Same as for application/xml. See RFC3023, section 3.2.
Restrictions on usage:
None
Security considerations:
As with other XML types and as noted in RFC3023 section
10, repeated expansion of maliciously constructed XML
entities can be used to consume large amounts of memory,
which may cause XML processors in constrained environments to
fail.
SVG documents may be transmitted in compressed form using
gzip compression. For systems which employ MIME-like
mechanisms, such as HTTP, this is indicated by the
Content-Transfer-Encoding header; for systems which do not,
such as direct filesystem access, this is indicated by the
filename extension and by the Macintosh File Type Codes. In
addition, gzip compressed content is readily recognised by
the initial byte sequence as described in RFC1952 section
2.3.1.
Several SVG elements may cause arbitrary URIs to be
referenced. In this case, the security issues of RFC3986,
section 7, should be considered.
In common with HTML, SVG documents may reference external
media such as images, audio, video, style sheets, and
scripting languages. Scripting languages are executable
content. In this case, the security considerations in the
Media Type registrations for those formats shall apply.
In addition, because of the extensibility features for SVG
and of XML in general, it is possible that "image/svg+xml"
may describe content that has security implications beyond
those described here. However, if the processor follows only
the normative semantics of this specification, this content
will be outside the SVG namespace and shall be ignored. Only
in the case where the processor recognizes and processes the
additional content, or where further processing of that
content is dispatched to other processors, would security
issues potentially arise. And in that case, they would fall
outside the domain of this registration document.
Interoperability considerations:
This specification describes processing semantics that
dictate behavior that must be followed when dealing with,
among other things, unrecognized elements and attributes,
both in the SVG namespace and in other namespaces.
Because SVG is extensible, conformant "image/svg+xml"
processors must expect that content received is well-formed
XML, but it cannot be guaranteed that the content is valid to
a particular DTD or Schema or that the processor will
recognize all of the elements and attributes in the document.
SVG has a published Test Suite and associated implementation
report showing which implementations passed which tests at
the time of the report. This information is periodically
updated as new tests are added or as implementations improve.
Published specification:
This media type registration is extracted from Appendix M of
the SVG 1.2 Tiny specification.
http://www.w3.org/TR/SVGMobile12
Additional information:
Person & email address to contact for further information:
Dean Jackson, Chris Lilley (member-svg-media-type at w3.org).
Intended usage:
COMMON
Author/Change controller:
The SVG specification is a work product of the World Wide Web
Consortium's SVG Working Group. The W3C has change control
over these specifications.
--
Chris Lilley mailto:chris at w3.org
Chair, W3C SVG Working Group
W3C Graphics Activity Lead
Co-Chair, W3C Hypertext CG
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